Database Views

Database views are querys on tables, that are stored on the dqatabase system. In eva/3 Application Builder views only serve for presentation and not for editing data.

In eva/3 Application Builder, Database views can be imported from the database to , displayed or created. Database views can be used as record source for Forms or Reports. They will be accessed like common tables in SQL statements.

A CREATE VIEW statement looks as follows:

CREATE VIEW (columnname1[,..]) viewname as (SELECT EXPRESSION)

viewname is not of interest in this cas, because it will be replaced by the previously entered View name.

At some databases the definition after CREATE VIEW is needed in special when SELECT EXPRESSION are used. By this, every selected column or expression gets an according column name.

When a new Database View was created, and the data was entered, it must be syncronized. By thes syncronization process, it will be checked if the view already exists. When that is true, the CREATE VIEW automatically will be replaced by ALTER VIEW.

When opening the editor page Results after changing without syncronization, it will cause an error.

The text will alwas be ignored when using the Database View. It is only used to edit the statement. Thats why the Database View alway must be syncronized with the database after every change.

Working with Databases
Creating a new View
Edit Databas View